Fluid read-out device



Aug. 17, 1965 s. A. FRANCIS FLUID READ-OUT DEVICE 2 Sheets-Sheet 1 FiledMay 15, 1963 INVENTOR mus; 4/?41Y4'IJ' ATT RNEYS Aug. 17, 1965 s. A.FRANCIS FLUID READ-OUT DEVICE 2 Sheets-Sheet 2 Filed May 13, 1963 g W7\\x m K INVENTOR 207054 4 @A/vc/J' fidlg 4249555 ATT RNEYS United StatesPatent 3,200,525 FLUID READ-OUT DEVECE Samuel A. Francis, Marion, Mass.,assignor to Francis Associates, Marion, Mass, a partnership Filed May13, 1963, Ser. No. 281,379 11 Claims. (Cl. 40-130) This application is acontinuation-in-part of my copending application, Serial No. 185,643,tiled April 6,

1962, now abandoned.

The present invention relates to character display devices in general,and in particular to a novel display device for the visual presentationof output information from a fluid device such as a pneumatic computer.

While recent emphasis in the computer art has been largely directed tothose devices operating on an electrical basis, and more particularly todigital computers employing sulch conventional circuit combinations ofAND gates, OR gates, NOR gates, flip-flops, shift registers, etc., etc,those skilled in the art will readily appreciate that there may beconstructed a hydraulic or preferably pneumatic functional equivalentfor each of these electrical arrangements. The construction of a digitalcomputer working upon the pneumatic principle employing the pneumaticequivalents of the aforementioned conventional digital circuittechniques affords many potential advantages in the computer field bothin cost reduction, compactness and reliability over the known electricaltechniques.

One form of the invention disclosed, includes a series of planes oftransparent material in which shaped numeral passageways are etched.Each numeral is provided with an inlet and outlet passageway for thepassage of a liquid therethrough. The planes are laminated together in amanner so that their respective etched numerals, as defined by thepassageways, are in a superimposed relation. The planes are edge-lightedat all times, and because of the difference in the refractive index oflight along the paths of the etched passageways at the edge of thenumerals, the edge lighting is dispersed and the numerals are thusvisible. The invention further provides means to blank out one or all ofthe numerals by selectively introducing into their respectivepassageways a liquid whose index of refraction is substantially the sameas that of the material in which the numerals are etched. As the clearliquid fills each etched path, the edge lighting will be transmittedthrough the fluid with no change in path. Therefore, each of the etchedpassageways thus filled will be invisible and display of any selectedpassageway may be readily accomplished by the mere removal or drainageof the fluid therefrom.

In another and preferred form of the invention, a simplified passagewayarrangement is employed wherein the numerical indicia desired to bedisplaced is formed as a groove in a side wall of a generallyrectangular chamber. In similar fashion, as in the preceding embodimentdescribed above, when the chamber is filled with a liquid having anindex of refraction similar to the material forming the chamber theoutline of the recessed numerical indicia will be invisible. Uponpurging the liquid from the chamber, the associated indicia in the sidewall will become clearly visible in the presence of edge or otherincident light rays.

Accordingly it is an object of this invention to provide means forvisually displaying output information from a pneumatic computer.

Another object of the invention is to provide a novel display meansresponsive to the respective fluid output pressures from a computer ofthe type envisioned employing the optical principles of edge-lighting incombination with transparent solids and liquids having similar indicesof refraction.

3,Zh,525 Patented Aug. 17, 1965 Yet another object of the invention isto provide a display device for a pneumatic computer wherein thecomponents of the display are similar in construction to the componentsemployed in the computer logic.

Yet another object of the invention is to provide a display devicewherein the character to be displayed is in the form of a passagewayformed in layer of transport material that is edge-lighted and isremoved from display by the filling thereof with a solution having anindex of refraction substantially identical with said transparentmaterial.

A further object of the invention is to provide character display whichis simple in design, rugged in construction and economical tomanufacture.

These and other objects and advantages of the invention will becomeapparent and the invention will be fully understood from the followingdescription and drawings in which:

FIG. 1 is an exploded schematic perspective of the invention;

FIG. 2 is a vertical section of a desk calculator type computer of thetype to which applicants novel display would be particularly useful;

FIG. 3 is an exploded perspective view of another and preferred form ofthe invention; and

FIG. 4 is a vertical section taken along line 44 of FIG. 3 as thearrangement of FIG. 3 would appear in normal assembled relationship.

The apparatus shown in FIG. 1 comprises a numerical display generallydesignated 18 having a plurality of layers or planes 12 made of anysuitable transparent material. Each of the layers 12 has etched orformed therein a series of recesses in the form of numerals designated,respectively, 14, 16, 18, 2t and 22. While in the example shown,numerical characters l through 5 are illustrated, it is to be understoodthat any number of individual planes 12 may be employed to produce thedesired series of superimposed characters and that other characters, notnecessarily numbers, may be similarly etched within the planes.

The numeral 2 designated 20, due to its etching into the surface of itsplane 12 forms a passageway in cooperation with the flat side of itsadjacent plane 12. The passageway in the outline of the numeral 2communicates with a connecting passageway 24 at its upper end and with asecond connecting passageway 26 at its lower end. The connectingpassageway 24 communicates with a check or float valve 28 placed inseries relation with a readout control which connects with an associatedcomputer readout passageway (not shown). While the aforementioneddescription has been directed toward the connections of the numeral 2 ofthe display, numeral 1 is also shown with similar connections, and it isto be understood that similar connections would also be connected toappropriate terminal portions of each of the other etched numerals 14,16 and 18.

The connecting passageway 26 communicates with a liquid reservoir 32containing a liquid 34 therein having an index of refractionsubstantially identical to the index of refraction of each of the planes12. The reservoir 32 is provided with a pressurization source 36 whichdirects compressed gas such as air to the uppermost portion of thereservoir. Disposed beneath the array of layers 12 is a light sourcedesignated 38. As shown, each of the characters and numerals 1, 3, 4-, 5and the decimal point designated 39 is filled with liquid 34 from thereservoir 32. The liquid 34 extends throughout the passageways 26, thecharacters and the passageways 24 up to their respective check valves28, which function to limit the flow of liquid and thereby isolate itfrom the computer passageway 3t Because of the light from the source 33,

each of the characters 1, 3, 4, 5 and the decimal point would beinvisible'in 1 16. 1 because of their identical indices of refractionwith that of the material of the planes 12. However, the numeral 2 (theelement designated Z) is shown void of liquid 34 due to the applicationof an overriding pressure through conduit S t check valve 28, conduit 2to return its fluid to the reservoir. Because the etched boundary edgesof numeral 2 will disperse light when it is not filled with liquid fromthe reservoir 32, the light from light source 38 will thus make When thecomputer output.

this numeral 2 visible. changes and alternatively pressurizes adifferent selected readout control passage 30, a different characterwill be cleared of its filling liquid to thus make it visible, whilefunction keys 42 on the upper surface thereof which operate to controlthe pneumatic calculating circuits contained in the laminated structure1 -1. Upon completion of the commanded computation, the structure 44would produce a series of pneumatic discharges into selected controlpassageways 311 of a plurality of displays 11 such as shown in FIG. 1.The desk calculator 40 also includes portions corresponding to thereservoir 311, edge light source 38 and air supply 36 schematicallyshown in FIG. 1. The calculator is provided with a mirror 46 so indirectviewing of the illuminated characters of the display 111 may beobtained. The area 48 includes the array of check valves 28 employed ineach of the output passages 30.

Referring to the preferred embodiment shown in FIGS. 3 and 4, a ninedigit or what is also called a nine-bit display is shown capable ofdisplaying either a zero or a 1 in each of the nine positions. Whilethis display is for a binary number system employing only zeros andones, it

should be understood that the principles of the invention mayreadily beapplied to a decimal number system including numerals zero through ninein each one of the nine-bits. I

In particular this embodiment comprises a plurality of individual layersof transparent plastic material laminated together into a unitary blockassembly. The necessary passages and chambers are formed in theirrespective sageway of a computer similar to the passageways 24 ofFIG. 1. Each chamber 116 also includesa lower depending drain portion120 which is formed to be in registry with the aligned apertures 122,122', and 122", formed in the adjacent plates. The aligned apertures122, 122' and 122" cooperate to form an elongated passageway from thebottom drain portion 120 of the chamber 116 for passage of fluidtherefrom into the reservoir chamber 142 formed in the reservoir plate141). Superimposed behind each of the chambers 116, and in fluidisolation therefrom, are a plurality of second chambers 130 formed in asecond separation plate 128. The intermediate plate designated 124includes a plurality of engraved or recessed zero numeral outlinesindicated at 126. Each of chambers 130 has a similar upper connectingpassageway 118 for the application of fluid pressure thereto'to expelthe liquid from the chamber 130 into the reservoir 142. The rearwall'ofeach of the chambers 130 is enclosed by a cover plate 132, which if madeof transparent plastic material is provided with a suitable forwardfacing black surface coating indicated at 134. Each of the chambers 130.is also provided with alower drain portion 136 which communicatesthrough a corresponding aperture d 138 formed in the rear cover plate132 to place each chamber 13% in fluid communication with the reservoirchamber 142. The rear wall of the display assembly is enclosed by asuitable plate 144 and the entire sandwich of layers may be securedtogether by any suitable means such as adhesive or by the bolts'146extending therethrough as shown.

Again, as in the embodiment of FIG. 1, the operation of the display isessentially identical. Under the influence of edge lighting neither ofthe numerals 112 or 126 will be visible when each superimposed chamber116 and .130 is filled with fluid. Upon purging of the fluid from eitherof the chambers 116 or 130 by application of a suitable downward airpressure through the selected passageway 11$, the respective numeralindicated at 112, or 126 will appear. This embodiment differsprincipally from the embodiment of FIG. 1 in providing a fluid chamberin commonwith the recessed numeral outline to facilitate.

the passage of fluid up to and out of the numeral passageways.

Thus it will be seen how applicants novel pneumatic display may beemployed in a computer having fluid pneumatic readout impulses. Whilethe invention has been described as being preferably employed with apneumatic computer, those skilled in the art will readily realize thatit need not be necessarily in combination with a computer, but could beused in any environment where visual display of fluid, data is required.Furthermore, while in applicants preferred embodiment the removal of theliquid 34 from the character passageway selected to be displayed isshown as being accomplished by air means, it is well within the scopeofthis invention to remove the liquid 34 having the similar index ofrefraction, from the character passageway by another liquid having adissirnilar index of refraction.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application'of the inventiveprinciples, it will be understood that the invention may be embodiedotherwise without'departing from such principles.

What I claim is:

1. A fluid operated visual display comprising a plurality of layers oftransparent material having a predetermined index of refraction, aplurality of individual passageway means in said layers having portionsdefining the boundaries of predetermined characters, said charactersbeing in superimposed relation, a light source for illuminating theedges of said layers to thereby illuminate the boundaries of saidcharacters, a reservoir for containing a supply of liquid having anindex of refraction substantially equivalent to the index of refractionof said layers, conduit means in communication between said reservoirand one end of each of said passageway means, means for applying apressure to the interior of said reservoir to transfer the liquidcontained therein through said conduit means to fill said passagewaymeans to render said means substantially invisible when said layers aresubjected to illumination from said light source, and

means to selectively remove liquid from predetermined 4. A displayaccording to claim .3, including checlc valve means in saidlast1mentioned conduit means to limit the flow of liquid from saidreservoir.

5. A display according to claim 3, wherein each of said layers includesa plurality of passageway means each of which is connected by individualconduit means to said reservoir.

6. In a fluid computer of the type having a visual read out display ofindicia and having a body of transparent material of a predeterminedindex of refraction and being adapted to be exposed to illuminatingmeans externally thereof, the improvement comprising passageway meanswithin said body having portions for defining the edges of the indicia,means for supplying a transparent liquid having an index of refractionsubstantially equal to the index of refraction of said body to saidpassageway means, and means for clearing said passageway means of saidliquid, said portions for defining the edges of the indicia beingrendered visible when said passageway means are cleared and said body issubjected to illuminating means, said portions defining the edges of theindicia being rendered substantially invisible when said passagewaymeans are supplied with a transparent liquid and said body is exposed tothe illuminating means.

7. A fluid operated visual display comprising a plurality of layers oftransparent material having a predetermined index of refraction, aplurality of fluid isolated individual chamber means in said layershaving portions defining the boundaries of predetermined charactersbeing in superimposed relation, a light source for illuminating theedges of said layers thereby illuminating the boundaries of saidcharacters, a reservoir for containing a supply of liquid having anindex of refraction substantially equivalent to the index of refractionof said layers, conduit means in communication between said reservoirand a lower portion of each of said chamber means, means for applying apressure to the interior of said reservoir to transfer the liquidcontained therein through said conduit means to fill said chamber meansto render said edge portions substantially invisible when said layersare subjected to illumination from a light source, and means toselectively remove liquid from predetermined chamber means to render theedge portions thereof visible.

8. A display according to claim 7, wherein said characters are numerals.

9. A display according to claim 8, wherein each of said layers includesa plurality of chamber means each of 6 which is connected by individualconduit means to said reservoir.

10. A fluid operated visual display for indicia comprising a body oftransparent material having a predetermined index of refraction,multiple superimposed chamber means within said body having portionsdefining the edges of indicia to be displayed when said body issubjected to edge lighting, means for illuminating the edges of theindicia, means for supplying a transparent liquid having an index ofrefraction substantially equal to the index of refraction of said bodyto said chamber means, and means for selectively clearing individualchamber means of said liquid.

11. A fluid operated indicia type visual display comprising a body oftransparent material having a predetermined index of refraction,passageway means within said body having portions superimposed over eachother and having portions defining the edges of indicia to be displayed,means for illuminating the edges of said indicia, means for supplying atransparent liquid to said passageway means having an index ofrefraction substantially equal to the index of refraction of said body,and means to selectively clear the liquid filling one or more of saidpassageway means.

References Cited by the Examiner UNITED STATES PATENTS 1,485,772 3/24 DuPont 8861 XR 2,489,751 11/49 Candler 88-61 2,612,078 9/52 De Lisio 88-612,621,430 12/52 Neville l06.22 2,703,547 3/55 Hardesty 40-130 X2,722,762 1l/55 Krajian 40130 2,751,584 6/56 Isborn 40-130 XR 2,783,6823/57 Swenson 88-61 EUGENE R. CAPOZIO, Primary Examiner. JEROME SCHNALL,Examiner.

10. A FLUID OPERATED VISUAL DISPLAY FOR INDICIA COMPRISING A BODY OFTRANSPARENT MATERIAL HAVING A PREDETERMINED INDEX OF REFRACTION,MULTIPLE SUPERIMPOSED CHAMBER MEANS WITHIN SAID BODY HAVING PORTIONSDEFINING THE EDGES OF INDICIA TO BE DISPLACED WHEN SAID BODY ISSUBJECTED TO EDGE LIGHTING, MEANS FOR ILLUMINATING THE EDGES OF THEINDICIA, MEANS FOR SUPPLYING A TRANSPARENT LIQUID HAVING AN INDEX OFREFRACTION SUBSTANTIALLY EQUAL TO THE INDEX OF